In this monograph, four youthful populations are examined in an effort to understand both their risk for substance abuse and the etiologic factors involved in such risk. The papers also describe potential intervention and prevention strategies consistent with the information available for each of these populations, which include children of substance abusers, juvenile delinquents, foster care youth, and runaways. In the panel format used at the technical review, each author presented his or her paper and there was then an opportunity for a reaction panel to comment. The reaction panel was comprised of seven persons in addition to the three other presenters, each of whom has some type of responsibility for planning and implementing prevention and treatment programs for adolescents. Chapter references